FIG. 1 is a circuit configuration diagram showing one example of a general pseudo-current source inverter. As shown in FIG. 1, the pseudo-current source inverter includes a chopper circuit ch, an input voltage Vdc inputted into the chopper circuit ch, a six-step inverter INV which is configured to receive a direct-current power outputted from the chopper circuit ch, and to perform 120-degree conduction, and a diode D1 connected in inverse-parallel to the chopper circuit section ch.
First, a direct current Idc is controlled by switching switching elements SW1 and SW2 of the chopper circuit ch, so as to make the input voltage Vdc and the chopper circuit ch serve as a control current source. The power is supplied to a motor M which is a load by switching operation of a semiconductor switch element of the inverter INV.
In the pseudo-current source inverter, the control current source and the inverter INV are separated, as mentioned above. The current control is performed in the chopper circuit ch of this control current source.
A Patent Document 1 discloses a pseudo-current source inverter which uses an input voltage Vdc and a chopper circuit ch as a control current source, and which drives an inverter INV by 120-degree conduction method.
Moreover, there is known an apparatus which employs a pseudo-current source inverter as an inverter for driving a PM motor in a hybrid system in which the PM motor is embedded in a turbocharger (a non-patent document 1).